In the twenty-first century you'd be hard pressed to find a piece of every day kit that doesn't have a power cell of some kind running it. Cellphones, tablets, laptops, MP3 players... they all need to be plugged in periodically to recharge. Under optimal conditions they can go two or three days in between top-offs but sometimes that isn't practical. Additionally, rechargable power cells have a finite lifetime and start to run dry faster and faster after two or three hundred recharges. This next bit of tech makes me wonder... a research team at Virginia Tech has figured out how to build fuel cells that replicate certain aspects of metabolism to generate electricity. Called biobatteries, they run on malodextrin (a sugar which is considered an equivalent to dextrose) because nature has shown that it has a fantastic energy density, is relatively stable, and the reactions to liberate the energy from the electron bonds are fairly simple. The Virginia Tech biobattery uses a complement of thirteen synthetic enzymes to liberate 24 electrons from each molecule of malodextrin, which if you do the math works out to a power density of about 0.8 mW/cm^2 and an energy storage density of 596 Ah/kg... that's an order of magnitude greater than the lithium polymer power cells in your cellphone or laptop. Chief reseearcher Y.H. Percival Zhang says that they're about three years away from being able to go into commercial production.